Method of reproducing engraved drawings



May 31, 1938. H. WIENEKE 2,119,190

METHOD OF REPRODUCING ENGRAVED DRAWINGS Filed Feb. 15, 1937 Hate w/Zh engraved /ines fng/"al/ed fines f///ed W/Z/L faZZg Mr and dusldover' W/Z/Z, a pawder hay/77g a ZZmn/ng anion The powder Z/"cmg e/Ped Z0 Zhe ge/aZ/n Myer mans/V22 Patented May 31, 1938 UNITED STATES PATENT OFFICE METHOD OF REPRODUCING ENGRAVED DRAWINGS Hans Wieneke, Berncastel, Germany 6 Claims.

When drawings of the highest degree of fineness (maps, engravings and the like) are to be prepared engraving instruments are used and one draws with them upon metal plates, stone or the like. If tracings are to be made according to already existing originals then preferably thin celluloid foils or the like are used and the drawing is engraved or cut with a needle in the said foil.

The present invention indicates a way of multiplying such engravings in a simple manner whilst avoiding the intaglio printing process;

In this new method the drawing is prepared the correct way round, that is to say non-reversed, with the needle or other engraving tools. The finished graving then has intaglio ink or the like rubbed in and is polished clean again. In this way a trace of fatty ink is left in the engraved lines or places.

This engraving is then dusted over with a powder having a tanning action. After the subsequent dusting off a small quantity of this powder remains adhering to the engraved places, more particularly to the fatty ink which has been rubbed therein.

If now the engraving prepared in this way is squeezed on to a moist gelatin layer or photo-' mechanical printing layer which has not been treated with bichromate then on this layer a tanned image is immediately formed which can be printed in a collotypic manner. The resulting prints attain the fineness of copper engravings. If closed areas are to be made printable then their contours are engraved whilst the interior area is painted with a weak oil or fatty ink; during the subsequent dusting operation the tanning dust then remains adhering to the painted surface and produces a printing image of the area on transfer to the colloid printing form.

As regards the powder to be used for the dusting operation it may be remarked that pure tanning substances are not suitable since these when transferred to the moist colloid layer attract much moisture from the latter and dissolve. As a result of this one obtains tanned images which are clogged up. Such pure or almost pure tanning powders have already previously been proposed for dusting reprints, but have not been found to be suitable. (Jaroslav Brazda of Prague, Austrian Patent No. 51,410 of 1911; Hermann Hurwitz of Berlin, Austrian Patent No. 87,296 of 1917.)

Hair sharp printed images are obtained with a powder which is made for example by dissolving about 20 parts by weight of chrome alum in water and mixing with one hundred parts by weight of a filler such as bole, kaolin, kieselguhr etc., and the whole dried and powdered.

The method provided by the present invention is illustrated by the accompanying drawing. In

(Cl. ll-41.5)

Figure 1 of the drawing is shown a plate bearing engraved lines. In Figure 2 the said lines are shown filled with fatty ink, powder with tanning properties adhering to the ink. Figure 3 shows a gelatin layer on a celluloid support after the engraved plate of Figure 2 has been applied thereto; the powder tans the gelatin and so a printing form is produced from which copies of the original engraving can be printed in the usual manner.

What I claim is:--

1. A method of reproducing images engraved on a clean ground consisting in filling the recesses of the engraving with an adhesive mass, applying to the engraving a dust having tanning properties comprising insoluble particles, removing the dust where not adhering to the adhesive mass, bringing the engraved ground into intimate contact with a moist colloid layer under pressure, whereby the dust on the engraved image tans said layer corresponding to the engraved image, and printing from the tanned image by the usual methods.

2. A method as claimed in claim 1 in which the adhesive mass is fatty ink.

3. A method of reproducing images engraved on a clean ground consisting in rubbing intaglio ink over the engraving, wiping the engraving clean so that ink is left only in the recesses of the engraving, applying to the engraving a dust having tanning properties comprising insoluble particles, removing the dust where not adhering to the ink, bringing the engraved ground into intimate contact with a moist colloid layer under pressure, whereby the dust on the engraved image tans said layer corresponding to the engraved image, and printing from the tanned image by the usual methods.

4. A method as claimed in claim 1 in which the insoluble particles in the dust consist of an inorganic substance. 5. A method as claimed in claim 1 in which the dust having tanning properties is an insoluble substance in dust form selected from the group consisting of: bole, kaolin, kieselguhr, which has been impregnated with tanning agent.

6. A method of reproducing images engraved on a clean ground consisting in rubbing intaglio HANS ill) 

